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<font face="DejaVu Sans Mono">I gave a super-fast & superficial
read to the answers. The GUI tool should exist, I can google it. <br>
<br>
The first answer was edited in 2017, the rest, as you say, is very
old. E.G. they talk about 'ipfw' which is one of the FreeBSD
firewalls and the main entry point to 'dummynet' but, if I
'apropos ipfw' in my macOS I find nothing. <br>
<br>
If the GUI works well enough, use that. dummynet is powerful but
requires several hours of study end experiments. <br>
<br>
bye<br>
n.<br>
<br>
<br>
<br>
</font>
<div class="moz-cite-prefix">On 9/13/19 10:02 PM, Phil B wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAMJMOejCtg=s+RzQZ7vQabLt6+YP0LFCV+dcAyk4Nj7+-G-AzQ@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">I'm sure you're right (assuming the GUI tool still
exists... the top answer is quite old.) Mainly I linked to the
answer since it seems to cover a spectrum of approaches which
might Eliot might find useful.</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, Sep 14, 2019 at 12:52
AM Nicola Mingotti <<a href="mailto:nmingotti@gmail.com"
moz-do-not-send="true">nmingotti@gmail.com</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF"> <br>
With high probability that GUI-tool is a wrapper to
'dummynet'. Anyhow, for sure it will be faster to deploy. <br>
<br>
n.<br>
<br>
<br>
<div class="gmail-m_3955315540927127760moz-cite-prefix">On
9/13/19 9:32 PM, Phil B wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">It sounds like simulating a terrible
(dropping packets) or painfully slow (kbps speeds)
network connection might be a more controlled way to
reproduce the issue: <a
href="https://apple.stackexchange.com/questions/24066/how-to-simulate-slow-internet-connections-on-the-mac"
target="_blank" moz-do-not-send="true">https://apple.stackexchange.com/questions/24066/how-to-simulate-slow-internet-connections-on-the-mac</a></div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Sep 13, 2019
at 11:16 PM Eliot Miranda <<a
href="mailto:eliot.miranda@gmail.com"
target="_blank" moz-do-not-send="true">eliot.miranda@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px
0px 0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">Hi All,<br>
<div><br>
</div>
<div> there is a VM bug in 64-bit Spur
with the Sista V1 bytecode set and full
blocks. The symptom is that when waiting
for a remote Monticello repository to
update and/or deliver a package version
the system crashes in JITTED code after
what appears to be some kind of wait.</div>
<div><br>
</div>
<div>This is a reliably occurring bug b ut
maddeningly difficult to reproduce. The
bug reliably occurs when interacting with
a remote rep[ository (e.g. <a
href="http://source.squeak.org/VMMaker"
target="_blank" moz-do-not-send="true">http://source.squeak.org/VMMaker</a>)
when the server is "cold", and hence makes
the image wait. Every time I have tried
to repeat the failing sequence the crash
has not occurre3d, I think because the
server is now "hot" and serves up the
version quickly. Today I even tried
shutting down my machine for over an hour
and rebooting. But I could not get the
crash to occur even though it seems to me
that every time I try it the first time in
the4 day it does crash.</div>
<div><br>
</div>
<div>This is an important bug to fix. If it
cannot be fixed then full blocks and Sista
V1 are not ready for use in the upcoming
Squeak release. I am looking for help in
debugging this.</div>
<div><br>
</div>
<div>- is anyone else uising the 64-bit VM
with full blocks and Sista V1 who sees
hard VM crashes? If so, under what
circumstances?</div>
<div><br>
</div>
<div>- is it possible to flush caches in
the <a
href="http://source.squeak.org/VMMaker"
target="_blank" moz-do-not-send="true">http://source.squeak.org/VMMaker</a>
server, or could people tolerate me
rebooting the server?</div>
<div><br>
</div>
<div>- is there a way of introducing network
delays in Mac OS that might help me induce
the bug?</div>
<div><br>
</div>
<div>- can anyone think of any other
strategies I might take to try and
reproduce this?</div>
<div><br>
</div>
<div>I may have to try and reproduce e the
bug in the simulator to have a chance of
identifying the bug. Does anyone have a
good enough mental model of the Monticello
server interaction and have energy to help
me figure this one out?</div>
<div><br>
</div>
<div>Here is some information from the last
crash I did see in the debugger (alas it
is incomplete; there are a number of
additional pieces of info I could have
collected).</div>
<div><br>
</div>
<div>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
thr b</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">*
thread #1, queue =
'com.apple.main-thread', stop reason =
EXC_BAD_INSTRUCTION
(code=EXC_I386_INVOP, subcode=0x0)</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
* frame #0: 0x000000010de5700a</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
frame #1: 0x000000010dd7b174</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
frame #2: 0x000000010dd45f1c</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
frame #3: 0x000000010dd44534</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
frame #4: 0x000000010dd44c60</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
x/10i 0x000000010de5700a</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica;min-height:14px"><br>
</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
call printStackCallStackOf($rbp)</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x7ffeefbdfc30 M Heap>upHeap:
0x11273ca90: a(n) Heap</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x7ffeefbdfc68 M Heap>add:
0x11273ca90: a(n) Heap</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x7ffeefbdfca0 M Delay
class>scheduleDelay:from:
0x1123ebfb8: a(n) Delay class</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x7ffeefbdfcf0 M Delay
class>handleTimerEvent 0x1123ebfb8:
a(n) Delay class</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x7ffeefbdfd20 M Delay
class>runTimerEventLoop 0x1123ebfb8:
a(n) Delay class</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica;min-height:14px"><br>
</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
x/10i 0x000000010dd7b174</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b174: 48 8b 55 10 movq
0x10(%rbp), %rdx</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b178: 48 89 ec movq %rbp,
%rsp</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b17b: 5d popq %rbp</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b17c: c2 10 00 retq $0x10</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b17f: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b180: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b181: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b182: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b183: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7b184: cc int3</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
print whereIs(0x000000010dd7b174)</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(char
*) $0 = 0x00000001000f83ff " is in
generated methods"</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica"><span
style="font-size:12px">(lldb) call
printCogMethodFor((void
*)0x000000010dd7b174)</span><br>
</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10dd7afc0 <->
0x10dd7b198: method: 0x112f23c10
selector: 0x112232c20 add:</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
print whereIs(0x000000010de5700a)</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(char
*) $1 = 0x00000001000f83ff " is in
generated methods"</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">(lldb)
call printCogMethodFor((void
*)0x000000010de5700a)</p>
<p
style="margin:0px;font-stretch:normal;font-size:12px;line-height:normal;font-family:Helvetica">
0x10de56ba0 <->
0x10de57078: method: 0x1126ec218
prim 23856 selector: 0x7ffeefbf3d20</p>
</div>
<div><br>
</div>
<div>this method ends up being the fitted
version of Delay class>><span
style="font-family:Helvetica;font-size:12px"> startTimerEventLoop</span></div>
<div dir="ltr"
class="gmail-m_3955315540927127760gmail-m_7948985732391852149gmail_signature">
<div dir="ltr">
<div><span
style="font-size:small;border-collapse:separate">
<div>_,,,^..^,,,_<br>
</div>
<div>best, Eliot</div>
</span></div>
</div>
</div>
</div>
</div>
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